This method, also known under the term “bolt setting,” is a reshaping joining method, in which a nail (bolt) is driven into the components to be joined at a high speed. It has the advantage that one-sided accessibility of the joining area is generally sufficient and pre-punched hole operations can often be avoided. Bolt setting is already being used as a reliable joining method in many areas like steel construction, facade construction, metal construction, ship building and the construction industry.
Nails (setting bolts), which are driven into steel, iron, sheet metal and similar metallic substances by means of setting devices in the form of powder force-driven cartridges, are known for example from DE 1 575 152, 1 940 447, 1 500 770. This type of nail normally consists of a nail head, nail shaft and an ogival nail tip, wherein the shaft can be provided with a surface profiling in the form of cross or arrow edgings, helically running ribbings and suchlike.
A nail (bolt) with a flat head, a cylindrical shaft and an ogival nail tip, which serves to fasten sheet metal plates on a metal part that is thicker than the sheet metal plate, is known from DE-GM 72 26 710. The nail is shot into the metal part through a prefabricated hole in the sheet metal plate. A recess for receiving the material protruding from it during the shooting into the metal part is provided in the head and/or in the shaft of the nail. In accordance with one embodiment in this document, the recess is provided on the bottom side of the nail head so that the edge of the sheet metal plate surrounding the prefabricated hole is bent up into the recess by the displaced material of the metal part. The metal part, the thickness of which is considerably larger than the length of the nail, completely surrounds the nail tip. The method disclosed in this document serves above all to fasten type plates to machines. This joining method is not suitable for fastening sheet metal plates to extruded sections with a closed cross-section or to components that have been reshaped through high internal pressure, as required for example in automobile manufacturing.
A joining method suitable for this application purpose is for example the so-called direct screwing, also known as “Flow Drilling Screw (FDS).” This method (see e.g. DES 102 48 427 A1, D139 22 684 A1 DE 39 09 725 C1 and DE 196 37 969 C2) uses a screw that has a flat screw head, a screw shaft provided with a thread and a screw tip. The screw is first placed on the components to be joined with a high speed and a corresponding contact force. The thus occurring frictional heat plasticizes the joining component substance to be reshaped. Crater- or toric-shaped appendages are thereby formed against and in the feed direction, into which the screw thread furrows out a counter-thread. The screw-in procedure is complete when the screw has penetrated the components and the screw head hits the upper component.